Tool-holder.



G. R. LANG.

TOOL HOLDER. APPLICATION IILED NOV. 82, 1907.

Patented July 6, 1909.

iyentoz 6207 6 m7 4 W7 4 abtomu cur-1m 20.. mommummn 1mm, 0.1:.

GEORGE E. LANG, OF MEADVILLE, PENNSYLVANIA.

TOOL-HOLDER.

Specification of Letters Patent.

Patented July 6, 1909.

Application filed November 22, 1907. Serial No. 403,304.

To all whom it may concern:

Be it known that I, GEORGE E. LANG, a citizen of the United States, residing at Meadville, in the county of Crawford and State of Pennsylvania, have invented new and useful Improvements in Tool-Holders, of which the following is a specification.

This invention relates to tool holders and consists in certain improvements in the construction thereof as will be hereinafter described and pointed out in the claims.

The invention is illustrated in the accompanying drawings as follows:

Figure 1 shows a side elevation of the tool holder. Fig. 2 a plan view of the tool holder. Fig. 3 an end view of the tool holder. Fig. 4 a section on the line 44 in Fig. 1. Fig. 5 a section on the line 55 in Fig. 2.

1 marks the body of the tool holder. The front face 2 of this body is slightly undercut so that its upper end extends forwardly beyond the lower end to give clearance to the tool. An undercut groove 3 is formed in the face 2, and a slot 4 extends into the body of the tool from the undercut groove toward the rear. A clamping bolt 5 is passed through the body transversely. One end of the bolt is provided with a slotted head 6, and the other end of the bolt with the nut 7.

The tool 8 is formed of the material triangularly shaped in cross section, the shape being preferably that of an equilateral triangle, so that each angle is sixty degrees. The under out faces 9 of the groove 3 are of less angle to the face 11 than sixty degrees, so that the edges 10 of those under cut faces contact the sides of the tool before the corners are engaged. The effect of this is to force the face 12 of the tool. 8 against the face 11 of the slot 3. The difference between the angles of the faces 9 and the sides of the tool are somewhat exaggerated in the drawings.

In addition to the clamping effect of the sides of the groove upon the tool, I prefer to provide positive means for locking the tool in the slot. The face of the tool has the notches 13. I The bolt 5 is cut away at 14 forming a tooth 15. When the bolt is turned so as to bring theface of the cut away portion 14 in line with the face of the slot 3, the tool may be readily inserted after it is in proper position. The turning of the bolt 5 swings the edge of tooth 15 into a notch 13, thus positively locking the tool in place.

The friction of the nut 7 is ordinarily sufficient to accomplish this purpose the thread being arranged in such direction that the tightening of the nut will swing the bolt into locking position. The slotted head 6 however, is provided as additional means for accomplishing the swinging of the bolt.

With tools formed of such steel as now commonly used it has been difficult to hold 1 the tool with sufficient rigidity to take what is known as a roughing cut. With the present holder it is largely lengthwise of the tool andv the clamping action of the holder so effective that roughing cuts can. be readily taken.

By using the triangularly shaped tool, the same tool may be utilized for cutting threads, the angle being the standard for this pur pose. YVith threads of different pitch it 1s desirable to change the curve at the base. With the present tool it is feasible to provide for different pitches of threads with the same tool by utilizing its different cutting edges and changing the curve of these edges. In the structure shown the edges 16 and 17 are differently arranged for this purpose and form the cutting points 18 and 19. All that is necessary is to reverse the tool to bring these points in roper osition for cutting. It is desirable w ere a p urality of edges are utilized in this way to provide notches on different faces of the tool to accommodate the different cutting edges. In the con struction shown I have shown a second series of notches 20, for operating with the cutting edge 19.

What I claim as new is:

1. In a tool holder, the combination of a body having a tool holding slot in its front face and a slot extending therefrom toward the rear of the body; and a clamping bolt extending transversely through the tool body at the rear of the tool holding slot and having an engaging portion extending such distance from the axis of rotation as to extend into the tool holding slot with the bolt turned to engaging position and said bolt having another portion extending such distance from the axis of rotation of the bolt as to clear the tool holding slot with bolt turned to disengaging position.

2. In a tool holder, the combination of a body having a tool holding slot in lts front face, and a slot extending therefrom toward the rear of the body; a clamping bolt extending transversely through the tool body immediately at the rear of the tool holding slot and EllLV- ing an engaging portion in the form of a tooth thereon extending such distance from the axis of rotation of the bolt as to extend into thetool slot with the bolt turned to engaging position, and another portion of such distance from the axis of rotation as to clear the tool holding slot with the bolt turned to' disengaging position, and a tool in the tool holding slot having notches into which the tooth on the bolt enters as it swings into the slot, said tool being free to move in the slot when the bolt is swung to disengaging position.

3. In a tool holder, the combination of a body having a tool holding slot in its face and a slot extending therefrom toward the rear of the body; a clamping bolt extendin through the tool body at the rear of the tool holding slot, said bolt being screw threaded, and having an engaging portion extending such distance from the axis of rotation of the bolt as to extend into the tool holding slot as the bolt is turned to engaging position, said bolt having another portion extending such distance from the axis of rotation as to clear the tool holding slot with the bolt turned to disengaging position, said engaging portion and the pitch of the screw thread having the relation to swing the engaging portion into the tool holding slot when the bolt is turned in the direction that the nut on the screw is turned to ti hten the bolt and to disengaging position when the nut is reversed, and a nut on the bolt operating on the screw thread.

In testimony whereof I have hereunto set my hand in the presence of two subscribing witnesses.

GEORGE E. LANG.

Witnesses:

CLINT DENSMORE, JOHN SOHULER. 

